1. Field of the Invention
This invention relates to an electronic circuit for detecting the peak and valley values together with the respective addresses of the peak and valley values in a digital signal and particularly to such electronic circuits which can be implemented as integrated circuits.
2. Prior Art
In digital signal processing it is sometimes desirable to determine the peak value, the valley value or a combination of both. To this end, various electronic circuits have been devised, but such electronic circuits have certain disadvantages.
In particular, most electronic circuits which have been devised are capable of either only detecting the peak value or only detecting the valley value. An example of such a circuit is contained in U.S. Pat. No. 4,311,960. However, such simple circuits are not capable of storing the address of the peak or valley value which they have detected and in some applications the address may be a useful or essential piece of information which would be required along with the peak or valley value. As a result, complicated additional circuitry must be added to determine the address.
In addition to the less complicated circuits described above which are only capable of determining either the peak value or the valley value, but not both, there exists circuitry capable of determining both the peak and valley values; an example of which is contained in U.S. Pat. No. 4,006,413. However, circuits such as those disclosed in this patent also have certain disadvantages in that they involve complicated circuitry which is implemented with a great number of discrete or integrated circuits and is therefore not capable of being implemented as an integrated circuit. In addition, circuits such as those disclosed in U.S. Pat. No. 4,006,413, while being able to determine the peak and valley values, are not capable of determining the addresses of the peak and valley values and again additional complicated circuitry would have to be added to determine the address.
In addition to the circuits described above, there does exist a circuit for determining the peak value and the time at which the peak value occurred. Such a circuit is described in U.S. Pat. No. 4,654,588. However, such a circuit has many of the disadvantages of the other circuits in that it is implemented with discrete circuit elements and separate integrated circuits, requires custom integrated circuits and cannot be completely integrated with simple and inexpensive to design circuits. Furthermore, the circuit shown therein is only a peak detector, does not include a valley value detector and is intended for use in high voltage (relative to the usual integrated circuit voltages) applications.